DataBind Controls to Vercel Data in C++Builder

The CData ODBC driver for Vercel makes it easy to integrate connectivity to live Vercel data with standard data access components in C++Builder. This article shows how to create a simple visual component library (VCL) application in C++Builder that connects to Vercel data, executes queries, and displays the results in a grid. An additional section shows how to use FireDAC components to execute commands from code.

Create a Connection to Vercel Data

If you have not already, first specify connection properties in an ODBC DSN (data source name). This is the last step of the driver installation. You can use the Microsoft ODBC Data Source Administrator to create and configure ODBC DSNs.

Using API Key Authentication

Vercel uses Bearer token authentication. You can use either a personal access token or an OAuth access token as the API key.

To obtain a personal access token:

1. Log into your Vercel account at https://vercel.com/
2. Navigate to Account Settings > Tokens.
3. Click Create Token, enter a name and expiration, and click Create.
4. Copy the generated token (it will only be shown once).

After obtaining your token, set the following connection properties:

• AuthScheme: Set this to APIKey.
• APIKey: Set this to your Vercel personal access token or OAuth access token.

Example Connection String

Profile=C:\profiles\Vercel.apip;AuthScheme=APIKey;APIKey=your_access_token;

Working with Teams

Many Vercel resources are scoped to a team. To scope all requests to a specific team, set the TeamId connection property to your team's ID. You can find your team ID by querying the Teams table or from the Vercel dashboard. Alternatively, you can specify TeamId in your SQL queries using the WHERE clause where supported.

Connecting to Vercel

Once the authentication is configured, you can connect to Vercel and query data from any of the available tables such as Projects, Deployments, Teams, and Domains.

You can then follow the steps below to use the Data Explorer to create a FireDAC connection to Vercel.

1. In a new VCL Forms application, expand the FireDAC node in the Data Explorer.
2. Right-click the ODBC Data Source node in the Data Explorer.
3. Click Add New Connection.
4. Enter a name for the connection.
5. In the FireDAC Connection Editor that appears, set the DataSource property to the name of the ODBC DSN for Vercel.

Create VCL Applications with Connectivity to Vercel Data

Follow the procedure below to start querying Vercel data from a simple VCL application that displays the results of a query in a grid.

1. Drop a TFDConnection component onto the form and set the following properties:

   • ConnectionDefName: Select the FireDAC connection to Vercel.
   • Connected: Select True from the menu and, in the dialog that appears, enter your credentials.

2. Drop a TFDQuery component onto the form and set the properties below:

   • Connection: Set this property to the TFDConnection component, if this component is not already specified.

   • SQL: Click the button in the SQL property and enter a query. For example:

     SELECT ,  FROM User WHERE  = ''
     

   • Active: Set this property to true.

3. Drop a TDataSource component onto the form and set the following property:

   • DataSet: In the menu for this property, select the name of the TFDQuery component.

4. Drop a TDBGrid control onto the form and set the following property:

   • DataSource: Select the name of the TDataSource.
5. Drop a TFDGUIxWaitCursor onto the form — this is required to avoid a run-time error.

Execute Commands to Vercel with FireDAC Components

You can use the TFDConnection and TFQuery components to execute queries to Vercel data. This section provides Vercel-specific examples of executing queries with the TFQuery component.

Connect to Vercel Data

To connect to the data source, set the Connected property of the TFDConnection component to true. You can set the same properties from code:

FDConnection1->ConnectionDefName = "CData Vercel ODBC Source";
FDConnection1->Connected = true;

To connect the TFDQuery component to Vercel data, set the Connection property of the component. When a TFDQuery component is added at design time, its Connection property is automatically set to point to a TFDConnection on the form, as in the application above.

Create Parameterized Queries

To create a parameterized query, use the following syntax below:

FDQuery1->SQL->Text = "select * from User where  = :";
FDQuery1->ParamByName("")->AsString = "";
FDQuery1->Open();

The example above binds a string-type input parameter by name and then opens the dataset that results.

Prepare the Statement

Preparing statements is costly in system resources and time. The connection must be active and open while a statement is prepared. By default, FireDAC prepares the query to avoid recompiling the same query over and over. To disable statement preparation, set ResourceOptions.DirectExecute to True; for example, when you need to execute a query only once.

Execute a Query

To execute a query that returns a result set, such as a select query, use the Open method. The Open method executes the query, returns the result set, and opens it. The Open method will return an error if the query does not produce a result set.

FDQuery1->SQL->Text = "select * from User where  = :";
FDQuery1->ParamByName("")->AsString = "";
FDQuery1->Open();

Related Articles

Below you can find other articles for using the CData ODBC Driver with RAD Studio, Delphi, and C++ Builder.

• DataBind Controls to Vercel Data in Delphi
• Viewing Vercel Data in RAD Studio Data Explorer
• Build a Simple VCL Application for Vercel Data